The invention relates to an endoscopic instrument for removing material, tissue and the like, and having a rigid hollow shank and a tool at the distal instrument end, the tool being driven in rotation via a drive shaft led into the hollow shank.
Instruments are known from the field of medicine, which may be introduced into body cavities via natural or artificially created access channels, in order to remove tissue there with these instruments. Such instruments usually comprise a hollow shank, which may be introduced through the access channel into the body cavity, at whose distal end a rotating tool for removing tissue is arranged in the extension of the hollow shank. Particularly with narrow access channels these instruments come up against limitations, when the tissue to be removed is located laterally of an access axis defined by the access channel.
Instruments are known in which the distal end region, with a tool located thereon, is designed in a rigidly angled manner. Such instruments are described, for example, in U.S. Pat. Nos. 1,677,337 and 4,646,738, as well as German published patent application DE 43 23 756 A1. These instruments with a rigidly angled hollow shank end and tool, however, are not suitable for endoscopic application, since they may not be led through a straight working channel of an endoscope.
Instruments which are basically suitable for this are described in U.S. Pat. Nos. 5,669,926; 5,851,212 and 6,464,711. These instruments have a straight hollow shank, which may be led through the straight working channel of an endoscope. The hollow shanks, with the tool arranged thereon, may be curved transversely away from their original longitudinal axis, for removing body tissue situated laterally of the hollow shank. However, the bending radius of the hollow shanks with these instruments is relatively large, so that the tools arranged at the distal end of the hollow shank may lie outside the scope of endoscopic optics, and an operative operation carried out with these instruments must, as a rule, be observed with additional optical means. A further disadvantage of these instruments lies in the fact that on application of a tool operated in a rotating manner, a drive shaft led through the hollow shank must likewise be bendable, i.e., must be designed in a flexible manner, whereby only relatively small torques at simultaneously low rotation speeds may be transmitted with these drive shafts. For this reason, these instruments are not suitable for removal of hard tissue, such as bone material.